The present invention relates to cotton picker spindles having a ceramic coating for increased hardness and smoothness.
A typical cotton picker includes a plurality of rotating barbed spindles which project into the plants to remove the cotton therefrom. A picker drum assembly includes a plurality of vertical picker bars which each support a column of rotatable picker spindles extending horizontally. Each spindle is elongated and includes a drive gear which is driven to rotate the spindle about its principle axis as the barbs engage the cotton. The cotton wraps around the spindles and is doffed therefrom by a doffing mechanism which includes a plurality of rubber doffers, one for each row of picking spindles.
A typical cotton picker spindle is fabricated from special heat-treated steel which is chrome plated to provide a hard, smooth surface. Several problems exist with these types of spindles typical of the prior art. Frost or rough spots can build on the spindle as the chrome plating is being carried out. Such irregularities must be finished out to prevent cotton from sticking to the spindles or the cotton will not doff properly and will be thrown back into the rows out of the harvesting compartment. Such a finishing process requires an additional step during manufacturing, and if the frost or irregularities are not removed, the spindle can be totally ineffective for harvesting cotton. Since a spindle is subjected to constant wear in a hostile environment, the useful life of the spindle is often less than desired even with the hard chrome plating. When the spindle is subjected to sand, which is much harder than the chrome plating, wear is accelerated. Replacing spindles is a time-consuming and expensive task, and reduces the productivity of the cotton harvester.
It is therefore an object of the present invention to provide an improved cotton picker spindle.
It is a further object of the invention to provide an improved cotton picker spindle which has an increased life expectancy as compared with at least most other prior art cotton picker spindles.
It is another object of the invention to provide a cotton picker spindle which has a smoother and harder surface than most prior art spindles. It is yet another object to provide such a spindle which does not require a finishing step during manufacture and which is yet devoid of frost or other irregularities which would result in inefficient picking and doffing of the cotton.
It is yet another object of the invention to provide a cotton picker spindle which is less expensive to manufacture than at least some prior art types of cotton picker spindles and yet has a smoother and harder surface than those prior art spindles.
In accordance with the above objects, a cotton picker spindle is provided with an elongated conical body made of hard metal and having a cone-shaped toothed picking end coated with a very thin coat of ceramic material. The ceramic material, preferably silica chrome alumina oxide or equivalent, coats the entire picking end including the teeth or barbs and the tip, and provides a very smooth, extremely hard surface which does not require finishing and which wears longer than conventional picker spindle surfaces. The ceramic coating can have a hardness greater than that of sand so that the spindle will wear much longer than a conventional spindle in sandy conditions. In one embodiment the entire picker spindle, including the cylindrical journal portion and the drive gear, is coated with a thin layer of ceramic. In an alternate embodiment, only the conical picking end has a ceramic coating. Although the coating is substantially uniform, a slight rounding effect on the top of the teeth or barbs is believed to provide better tooth wear and more advantageous hooking and better doffing action.
These and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the description which follows and from the drawings.